Comparison of polyvinyl chloride and elastic stannum stylet extraction forces with various lubricants: a simulation study

BACKGROUND Stylets are the most frequently used devices for tracheal intubation, but can be a source of postoperative pharyngeal pain or hoarseness. In this study, we evaluated extraction forces between polyvinyl chloride (PVC) and stannum (Sn) stylets with various lubricants. FINDINGS Using a manikin, we compared extraction forces between PVC and Sn stylets under four different conditions: without lubricant, 3 ml of water (water), three sprays of 8 % lidocaine (lidocaine), and olive oil. A force measuring device was used to accurately measure the extraction force for stylet removal. The extraction force was significantly smaller with the Sn stylet compared to the PVC stylet, regardless of the lubricant used for all three tracheal tubes with different diameters tested (P < 0.05). In comparisons by lubricant, lidocaine and olive oil resulted in significantly lower extraction forces than with no lubricant or water with the PVC stylet for all tracheal tubes tested. In contrast, there were no significant differences in extraction force by lubricant for the Sn stylet across all tracheal tubes tested. CONCLUSIONS The Sn stylet required less extraction force compared to the PVC stylet, regardless of the lubricant used.